Combined telephone and telegraph system



March 11, 1952 L. M. POTTS COMBINED TELEPHONE AND TELEGRAPH SYSTEM 15 Sheets-Sheet 1 Original Filed June '7, 1947 NMKOE Nhm #mm m mon Nm mum LOUIS M. POTT$,DECEASED hon MARTHA W.C. POTT$,EXECUTRIX ATToafiiY March 11, 1952 L. M. POTTS COMBINED TELEPHONE AND TELEGRAPH SYSTEM 15 Sheets-Sheet 2 Original Filed June 7, 1947 in MN m mm INVENTOR LOUIS M. POTT$,DECEASED MARTHA W.C. POTTSgx TRIX wow wow

vmfo mn March 11, 1952 L. M. POTTS 2,589,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June '7. 1947 15 Sheets-Sheet 3 mmm mmm 6N NwN INVENTOR LOUIS M. POTTS,DECEASED B MARTHA w.c. POTTS,EXECUTRIX ATTORNEY March 11, 1952 M. POTTS 2,589,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June 7. 1947 15 Sheets-Sheet 4 FIG. 6

INVENTOR LOUIS NI. POTTSQECEASED MARTHA W.C. PUTTSZEXECUTREX ATTORNEY March 11, 1952 M. POTTS 2,589,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June '7, 1947 15 Sheets-Sheet 5 INVENTOR -LOUIS M. POTTS,DECEASED Y MARTHA W.c.'POTTS,ExEcuTR|x a ATTORNEY March 1952 L. M. POTTS 89,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June 7. 1947 is Sheets-Sheet 6 INVENTOR LOUIS M. POTT$,DECEASED BY MARTHA W. C. POTTS,EXECUTRIX Z1 WM H7 ""ORNEY March 11, 1952 L. M. POTTS 2,589,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June '7. 1947 15 Sheets-Sheet 7 INVENTOR LOUIS M. POTTS, DECEASED BY MARTHA w. c. POTTS,EXECUTR|X ATT RNEY March 11, 1952 1.. M. POTTS 2,539,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June '7, 1947 15 Sheets-Sheet 8 INVENTOR LOUIS M. POTTS,DIECEASED Y MARTHA w. c. POTTS,EXECUTRIX ATTORNEY 15 Sheets-Sheet 9 L. M. POTTS COMBINED TELEPHONE AND TELEGRAPH SYSTEM FIG. 22

l02-4 Q2 2 I031 I02 3 March 11, 1952 Original Filed June '7, 1947 INVENTOR 'LOUIS m. POTTS,DECEASED MARTHA w. c. POTTS,EXECUTR|X BY 2 ATTORNEY March 11, 1952 1.. M. POTTS 2,589,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June 7. 1947 15 Sheets-Sheet 10 FIG. 24

F\G.28 F1629 INVENTOR LOUIS M. POT TS,DECEA8ED MARTHA w.c. POTTS,EXECUTRIX FIG 3| BY TTORNEY March 11, 1952 L. M. POTTS 2,539,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June 7. 1947 15 Sheets-Sheet 11 FIG. 25

3 FIG FIG FIG FIG INVENTOR LOUIS M. POTTS,DECEASED 25 26 27 BY MAR HAW. c. POTTS,EXECUTRIX TTORNEY March 11, 1952 L. M. POTTS 2,589 131 COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June '7, 1947 15 Sheets-Sheet l2 INVENTOR LOUIS M. POTT$,DECEASED MARTHA W. C. POTTS,EXECUTRIX A ToRNEY March 11, 1952 1.. M. POTTS 2,589,131

COMBINED TELEPHONE AND TELEGRAPH SYSTEM Original Filed June '7, 1947 15 Sheets-Sheet l3 [NIH NH H 1/ Mil/H H W mvsmoa LOUIS M. PoTTspscsAsEo Y MARTHAW.C. POTTS,EXECUTR!X TTORNE'Y FIG. 27

March 11, 1952 L. M. POTTS COMBINED TELEPHONE AND TELEGRAPH SYSTEM 15 Sheets-Sheet 14 Original Filed June 7, 1947 WATTORNEY m R T m w mm 9 H. m m M E E E E8 V D T S N "H P Nam, M F M M .5 w s T w R A w. M it m E U 1 "I l m ow-.\ T I M h mm muKmmKwi 03% V03. o: FL h m tn :9 En \m5 1. 6 2% am March 11, 1952 L. M. POTTS 2,589,131

COMBINED TELEPHGNE AND TELEGRAPH SYSTEM Original Filed June '7. 194'? 15 Sheets-Sheet l5 FIG. 29

livam'oa' LOUIS M. POTTS,OECEASED MARTHA w.c= POTTS,EXECUTRIX AT RNiY Patented Mar. 11, 1952 UNITED STATES PATENT OFFICE commnnn TELEPHONE AND TELEGRAPH SYSTEM Originalj application June 7, 1947, Serial No.

7535265. Divided and this application November 5, 1948, Serial No. 58,501

8.Claims.

This invention relates to combined telephone and telegraph systems and.more particularly. to the use in such systems. of combinedtelephone and. telegraph. sets.

This application is a. division of. copending appiication Serial. No. 753,265, filedaJune. 7:, 1947, nowU. S. PatentSerialNo; 2,522,462aof; September 12, 1950.

An object of the. presentinvention is, toprovideprinting telegraphv apparatus. adaptable for use instandard. telephone. systems.

Another object of the present invention is to provide in a combined: telephone and. telegraph system, printing telegraph. apparatushaving no moving partsexcept while telegraph signals are being transmitted.

A. further. object of the invention, is. to provide suitable circuit modifications at a telephonesubscribers station and. ata telephone exchange of a standard telephone system which. enables com: bined telephone and;telegraphservice to be maintained.

Aieature of: the invention is to provide a novel form of telegraph. transmitter, especially designed for use in the present combined- 4 phone and telegraph. system.

Another feature. of. the invention. is the provi sionof a novel. form; of receiving selector for. a printer havinga. type segmentwhichis movable in rotary and axial. directions to a; finalpyinting position.

still another featureof; the invention is the use of a vibrating motor fordriving printing t raph apparatus; in. which the motor t rest excep urin actual; tele raph c mm n cation intervals.

Other objects, featuresand advantages of the invention, although.not-specifically recited; above, will appear asthe invention is described de tail.

The s nt; n ntion. provid s. t elepho e subscribers stations, telephone and telegraph s ts m ined ntQ- neunit. Each t ra s t which is of the fiveunit code start-stoptYDQ includes a transmitter and a receiver which are driven by a vibrating: motor utilizing signaling current for its operation. The printer is pro vided with a typesegment movable in rotary and axial directions to a final printing position under the control of a novel form of selector. The printing telegraph apparatus is quiescent except during actual telegraph communication intervals.

To communicate with another subscriber, the calling subscriber removes a telephone handset from a cradle positioned on top of the unit. After 2 hearing. the dial tone, the calling; subscriber; knows. that a connection has been made by the usual. exchange switching equipment to an idle exchanger sender; circuit. The sender circuit utilized in the present invention is a modified formof sender circuit which is responsive to telegraph signals originating at the telegraphtrapsmitter. of a. calling subscriber. By depressing predetermined keys of the transmitter thecalling subscriber may operate an idle sendercircuit and thereby become connected with the desired called subscriber in a manner similar to usual telephone dialing practice. The connection established betweenthe calling and calledsubscribers includes modified district, selector and incoming circuits. The circuit Whichgconnects the calling and called subscribers includes modifled district selector and incoming. circuits.

A more thorough understanding of the inven: tion may be hadby reference to the detailed description which follows when readin conjunction with the drawings, wherein:

Fig. 1 is a left end elevational view of the combined telephone and telegraph unit taken on the line l-l of Fig. 2;

Fig. 2 is a plan view of; the apparatus shown in Fig. 1;

Fig. 3 is a plan view of the receiver selector and printer;

Fig. 4 is an enlarged detail view showing the operation of certain contacts involved in the invention;

Fig. 5 is a detailedview of the type segment;

Fig. 6 is a detailed View of a portion of theselector mechanism which controls the rotary position of the. type-segment;

Fig. 7 is a detailed view of another portion of the type segment;

Fig. 8 illustrates a case shifting operation;

Fig. 9 is a detailed view of a part ofthe selector mechanism which controls the. axial position of the type segment;

Fig. 10 illustrates the print hammer and tape feeding mechanisms;

Figs. 11 to 17 show various positions of a portion of the selector mechanisms which control the initial rotary p sition of the type segment;

Fig. 18 is a detail view of the vibrating motor;

Figs. 19 and 29 are detail views of the transmitting contacts;

Fig. 21 is a detail view showing particularly the stepping pawls which are operated by the vibrating motor;

Fig. 22 is a view showing the various cams used, in the receiver selector;

Fig. 23 is a detailed perspective view of the vibrating motor;

Fig. 24 is a schematic circuit illustration of a subscribers station;

Figs. 25 to 2'7 illustrate the exchange sender circuit employed in the present invention;

Fig. 23 shows a modified telephone district selector circuit;

Fig. 29 shows a modified telephone incoming circuit;

Fig. 30 shows how the drawings are arranged when a subscriber is connected to the exchange sender circuit;

Fig. 31 shows how the drawings are arranged when a subscriber is connected to another subscriber by means of the modified district selector and incoming trunk circuits; and

Fig. 32 is a schematic representation of the type segment.

With reference to the drawings, a detailed description of the invention will be undertaken. The main component parts of the combined telephone and telegraph unit shown in Figs. 1 and 2 are a telephone 3!, a telegraph transmitter 32, a telegraph receiver 33, a vibrating motor 3 3, and a keyboard 35 which controls the operation of transmitter 32.

The vibrating motor 35 which is best illustrated in Figs. 18 and 23 will first be described. It somewhat resembles the motor disclosed in the patent of L. M. Potts, No. 2,360,579. A magnetic field for the motor is provided by pole pieces St and 37 of a permanent magnet 38. Fast to a raft 39, suitably journaled on supporting members ii and 32, Fig. 23, is a bipolar armature 43 which includes a soft iron core id extending through winding it, the armature 43 being of magnetic material except forthe core 4d. Mounted concentric with shaft 39 is a coil spring 53,

one end of which is fixed to an oscillating disc it) by means of lug (not shown), the other end being secured in journaled plate 52 by means of an adjustable lug 53. Adjustable lug 53 is provided to increase or decrease the effective number of turns or fractions of turns of coil 58 which will be free to vibrate as will later be explained.

Armature as is designed to oscillate between pole pieces 36 and 31 in response to current reversals received by winding it as will later be described in detail. The terminals of winding ii? are suitably connected to conductor garter springs 5% which are attached to supporting member '32, Fig. 23. This enables electric conduction to be maintained to winding it despite the oscillation of armature 43 and its windin it. In the rest position of the apparatus disc dd is latched up at its notch 56 by means of stop lever 57 which is pivoted at 58 and has a follower arm 59 for engaging the periphery of cam ti carried by driving shaft 66. At this time stop lever 57 retains spring coil 48 under tension. Stop lever 5? is urged, by means of spring 52, in a counterclockwise direction as viewed in Fig. 18. Also pivotally mounted on shaft; 58 is a trip lever E53 which is urged in a clockwise direction by means of a spring 64 which is stronger than spring 52. Normally, armature 6'5 of selector magnet cl which is pivoted at points 68 (see Fig. 1) is in blocking relationship with the lower end of trip lever 63.

On receipt of a start impulse by selector magnet 5?, armature 56 moves upwardly to a position opposite a notch 63A and thereby enables spring t l to draw trip lever 63 to the left (as viewed in Fig. 18) since its projection it is free to enter notch 72 of cam 13. It might be mentioned at this time that the cams carried by shaft 6% are designed to function during two signal code combinations in each complete revolution so that the peripheries of the cams are the same at diametrically opposite points as illustrated in Fig. 22. When trip lever 83 moves to the left, by means of its pin 6Q, it pulls stop lever 51 also to the left, enabling the latter lever to withdraw its hooked end if from notch 56 of disc 59. This releases coil spring 43 for vibration. Spring 48 is tuned to vibrate at the same frequency as the alternating current received by winding 46 of armature it. Thus. when the disc it is locked, energy is stored in coil spring as and when it is released it immediately vibrates at full amplitude since the winding it receives alternating current of the same frequency at this time in a manner to be hereinafter described.

When stop lever 51 is pivoted clockwise as explained, the pointed end of its follower arm 59 is moved out of notch i i to the high part of cam Bi as shaft cc is stepped counterclockwise in a manner to be hereinafter explained. During one half revolution of shaft 80, disc 419 makes three complete oscillations and at the termination of the third oscillation stop lever 51 by means of its hooked end H engages in notch 56 of disc it. At this time selector magnet 67 will be in a balanced condition (as will later be explained) and armature 68 will have assumed a position to block trip lever 63. It will be understood that cam 55 is provided with diametrically opposite notches "it which enable the pointed end of follower arm 59 of lever 51 to pivot counterclockwise ,after each half revolution and by means of its hooked portion H engage notch 56 of disc Q9.

The stepping of the shaft Ell will now be described. Oscillating disc 29 carries a pin '16 which engages the forked end ll of a pallet is which is pivoted at 19. Pivoted respectively at 19 on pallet if; at H and 32 is a pair of stepping pawls 33 and S l- (Fig. 21) which drive the ratchet,

86 fast to shaft t8. During one half revolution of shaft 6t, each pawl 33 and 86 operates three times, moving ratchet 86 one half of a tooth during each stepping operation. As pawl 8G, for example, completes its forward stroke after having stepped ratchet 86 a distance equal to one half of a tooth, pawl 83 will have completed its return stroke and be ready to push on the same tooth just advanced by ratchet 8t and thus continue to advance it another half tooth. Meanwhile, the return stroke of pawl at will place it in a position to advance the next succeeding tooth and so the cycle continues. It is now clear that as disc d9 vibrates, pallet l8 will be oscillated and shaft Bil will he stepped six times for one half of a revolution or twelve times for a complete revolution. Springs 81 and 88 are provided on pawls 83 and 84 respectively to insure their engagement with the teeth of ratchet 86. It is apparent from the foregoing that the utilization of both the to and fro movements of the oscillating disc 49 for stepping operations enables a current of one half the frequency used of a five unit code in a start-stop system of telegraphy. The first two elementsof a given signal code combination determine the initial rotary position of a type segment IBI in a manner now to be described.

In order that the ensuing detailed description may be more readily followed, a brief outline of the operation of type segment IGI will be given. Type segment IdI is designed to move in response to the first two signal elements of a code combination to one of three rotary positions or it may remain in the zero position as shown in Fig. 6. This provides four possible-initial rotary positions in one case position and since the type wheel in the instant invention may be shifted in two case positions, eight possible initial rotary positions may be obtained. In response to the fifth signaling element of a code combination after the initial rotary position has been determined by the first two signal elements the type wheel may be stepped one half or one and a half steps further to a final rotary position to thus give a choice of two characters after the initial rotary position has been determined. lhe third and fourth elements of a signal code combination determine whether the type segment will remain in its zero axial position or whether it will be moved one, two, or three positions in an axial direction, giving a total of four possible axial positions. Obviously then, the type segment may occupy a total of thirty-two different printing positions in each case position.

First to be described will be the operation of type segment IIJI in the figures case, position represented schematically in Fig. 32. Carried by the shaft 8%, the step-ping of which was previously described above, is a selector cam I82I which operates its associated selector lever IIES-I (Fig. 1). It should be noted, as is clearly shown in 3, that earn IIl2-I is positioned to the rear of a similar cam IQZ-Z while selector lever I93I is positioned behind a lever I 93-2. Levers I03I and 533-2 are similar except near their lower ends whereat lever Ilia-I extends downwardly beyond lever loll-2 for a short distance and has formed thereon a notch I04. Springs IDB tend to pull levers IQS-I and I032 upward and to the left as viewed in Fig. 6 on the fixed rod IIII.

When the first element of a signal code combination is marking, armature I58 of selector magnet e; moves downwardly from a position opposite notch I34 of selector lever IG3I to block the latter from moving to the left (as viewed in Fig. 6) when cam Il'i2-I presents its notch I08 to the projection I68 of selector lever IIJ3I. As a consequence, sel ctor lever IIJ3I remains in the position shown in Fig. 6 and as the high part of cam IG2--I engages projection I09 of selector lever I33 I, the lower part of this lever will move outward with rod IB'I serving as a pivot point. Pivoted about a fixed shaft I I I is an actuating lever II2-I carrying at its lower end a pin which extends through a bifurcation II4 of a floating lever IIS. It is to be understood that in the present invention, actuating lever I iii-I will remain in the position assumed dur ing reception of the previous signal code combination. Thus, if lever II2I had remained in the position shown in Fig. 6, it would now be moved outwardly at its lower end as the part II! of selector lever III3I pressed against it. At this time lever I I 8 which is pivotally mounted on lever III; by means of socket connection II9, moves to the right since pin II3 will now pivot lever H6. counterclockwise. At. its freeend lever II8 carries a pin I2I which is engagedin alslot; I22 of a. slide rack I23 mounted on pin I24, and.

having its teeth I26 in engagement witha pinion I21 attached to shaft I28 which supports a.

sleeve I25 (Fig. 2), to the front endof which is secured the type segment IOI. When lever H8 moves to the right as described, its pin I2I causes slide rack I23 to be moved to the right and type segment IIII to be rotated to two thirds of its full distance for the initial rotary position in the case position now being described; As slide rack I23 moves to the right and rotates pinion I21 clockwise (as viewed in Fig. 6)- a second slide rack I29, slidably mounted on pins I24 and I3I and having teeth I32 in engagement with pinion E21, moves idly to the left. In the case position now being described, slide rack I29 moves idly back and forth according to the operation of slide rack I23 but when the selector shifts to the other case position, as will hereinafter appear, slide rack I23 will move idly back andforth as rotation of the pinion I21 is accomplished by the teeth I32 of slide rack I25.

When the first element of a signal code combination is spacing, armature 66' will remain in the position adjacent the notch I04 of selector lever I Il3i. Now as shaft 60 rotates, selector lever I33I will move to the left (as viewed in 6) as its projection "19 enters notch I08 of' cam IGEE-I under the influence Of spring I96. As projection I33 of selector lever I03I moves past the edge of rod I34, the selector lever I03I will move upwardly under the influence of spring.

- tom since pin H3 carried by lever II2-I engages bination is marking, armature E5 of selector mag net 57 will move out of blocking relationship with respect to the lower end of selector lever Ifi32, allowing this lever to move to the left and upwardly, as previously described in connection with selector lever IIl3I. Projection I33 of selector lever IIl3-2 now moves around the rodv I34 and as the high part of cam IIl2-2 engages projection I69 of selector lever I63.2, the latter lever will move to the right at the top, rod I34 acting as a pivot point. Projection I38 of selector lever IG32 will engage the upper end of a lever II2-2 also mounted on shaft III, and swing it out at the top (assuming it was remaining in at the top from the previous signal code combination). At its upper end, lever II22 carries a pin I38 which engages in the upper bifurcation I39 of lever H6 and thus as lever II22 moves out at the top, it will also carry lever I IS outv at the top. Lever I I8 by means of socket connection I I9 is connected to lever I I6 at such a point that when it moves out at its lower end, type segment IIII moves two thirds of its possible distance andwhen it moves out at the top, type segment IilI moves one third of its possible distance in the case position now to be described. Therefore, when the second element of a code combination is marking, lever M3 by means of pin IZI will push slide rack I23 to the right one third of its distance in this case position. At this time, slide rack I29 will move idly to the left a' similar distance.

When the second element of a signal code combination is spacing, armature 56 will block the lower end of selector lever I13-2, causing this lever to move out at its lower end with rod I9? serving as a fulcrum as described in comiection with selector lever IIi3-'I. As projection II! of selector lever 13-2 engages the lower end of lever II22 (assuming the lower end of lever II22 remains in from the previous signal code combination) it will be moved outward at its lower end. Since pin I38 carried by lever I I2-2 is engaged in the upper bifurcation I39 of lever I I5, the latter lever will move inwardly and carry lever IIB to the left thereby drawing slide I23 to the left and moving the type segment IGI counterclockwise one position.

From the foregoing it is now apparent that if the first and second elements of a signal code combination are spacing, type segment Iill will remain in the position shown in Fig. 6. If the first element is spacing and the second element is marking, type segment It! may move one third of its possible distance (Fig. 11) in this case position. If the first element is marking and the second element is spacing, type segment IIiI will move two thirds of its possible distance, Fig. 12.

If the first and second elements are both marking, type segment IEII will move three thirds or its full distance (Fig. 13). Thus, there are four possible initial rotary positions for type segment IQI, determined by the aggregate motion produced by operation of levers II33I and I53-2 in response to the receipt of the first two elements of a signal code combination received by selector magnet 61.

Since the fifth element of a signal code combination determines the final rotary position of type segment IIBI, its associated selector mechanism will be described prior to the part of the selector mechanism operable during the third and fourth element periods to control the axial position of the type segment. After the initial rotary position of the type segment IIII has been determined according to the first two signal elements, the type segment occupies an axial position determined by the third and fourth elements as will be described later. With particular reference to Fig. '7, the final rotary positioning of type segment II] I in response to the fifth impulse will now be described. In response to a marking impulse, armature 56 moves downwardly allowing projection I33 of selector lever [43-5 to move around rod I34 as previously described in connection with selector lever I532. The high part of cam Iii2-5 will push against projection I89 of selector lever Ii35, causing it to move out to the right at the top with rod I34 acting as a pivot point. When this occurs, flange I4I of bell crank I42 which is pivoted on rod It? will be encountered, causing the bell crank I42 to pivot in a counterclockwise direction. The laterally extending arm of hell crank I42 carries an adjustable stop I43 which will at this time be lifted out of the path of an engaging surface I44 of bell. crank I45. Bell crank I45 is pivoted at I I I and has a follower arm I41 which pursues the periphery of cam I48 under the urging of a spring I49. When the follower arm I47 of bell crank I46 moves toward the low part of cam I48, engaging surface I5I of bell crank I45 will engage a suitably mounted adjustable stop I52, since stop I43 Was lifted out of the path of engaging surface I44 as explained. Pivoted at I53 to bell crank I46 is a relatively long stepping pawl I54 which is urged toward engagement with the teeth of ratchet I55 by means of a spring I5I. Pawl I54 is equipped with a bent over frontwardly extending portion I58, so that regardless of the axial position of ratchet I55, the teeth of this ratchet may be engaged and stepped by pawl I54. Ratchet I55 is rigidly connected to the rear end of sleeve I25 mounted for a limited rotatable movement about the shaft I28 as will immediately hereinafter appear. To the front end of sleeve I25 is fixedly secured the type segment IllI. A leaf spring I59 (Fig. 5) extends across type segment IIlI and is rigidly clamped to shaft I28 by means of a segmental block I5I. Under the aforementioned marking condition, the stroke of pawl I54 will be limited by stop I52 and ratchet I56 will be stepped one and a half teeth. This causes the flexing of spring I59 since ratchet I56 and type segment IIiI are mounted on a common sleeve I25 and the type segment I5I is moved a distance corresponding to one and a half teeth of ratchet I56. Shaft I28 is at this time held against rotation, since the high parts of selector cams I52I and IIl2-2 are pressing against the projection I09 of selector lever Its-I and I632 and by means of slide rack I23, pinion I2! is held in the position selected during the first two impulses.

However, when the fifth element of the code combination is spacing, armature 66 will block the lower end of selector lever I03-5 and the latter lever will be moved outwardly to the right at its lower end. This action is insufiicient to raise stop I43 out of the path of engaging surface I44 and consequently when bell crank I46 pivots counterclockwise, the stroke of pawl I54 will now be shorter and will advance ratchet I55 only one half of a tooth. Again spring I59 will flex but not as much as when ratchet I56 is stepped one and one half teeth.

In order that the foregoing explanation may be more clearly understood, reference should be had to the schematic illustration of type segment Ifll shown in Fig. 32. Numeral I represents the :position occupied by type segment IIlI when the first two signal impulses are spacing and the type segment IIlI remains in its zero position as described. Numeral 2 represents the position occupied by type segment IllI when it is stepped one third of its possible distance. Numeral 3 represents the position occupied by type segment IOI when it is stepped two thirds of its distance. Numeral 4 represents the position occupied by type segment IIII when it is stepped three thirds or its full distance. From any of the positions just mentioned, the type segment IIiI may be stepped during the fifth impulse either one half step to a character row 5 or one and a half steps to a character row 6.

The axial positioning of type segment IOI in response to the third and fourth signal elements of a signal code combination will now be described. Since the mechanism for positioning the type segment IllI axially is substantially the same as the mechanism responsive to the first two impulses, it is felt that a detailed description of its operation is unnecessary. It appears sufficient to state that according to the operation and I68.

ratchet cams Ii 2'3, IO24 (Fig. 9) lever I63 (equivalent to lever H5) will remain. where it is or be moved one, two, or three positions depending on the signals received for the third and fourth signal elements. Lever is; pivotally supports one end of lever I6 (equivalent to lever H8) which is pivotally connected at its other end at I65 to a slide rack slidably mounted on pins it; Near the right end of slide rack 555 (Fig. 2) is a rearwardly extending projection ififi having teeth I'lI in engagement with pinion H2 which is fast to a stub shaft H3. Shaft carries a second pinion H4 which engages a slidable rack I16 normally urged toward the rear of the apparatus by a suitably attached spring iil. Rack I16 has integrally formed thereon a pair of projections H8 which straddle a part of the I56 which was previously described. Thus, according to the third and fourth impulses received by selector magnet 6i, rack II'd may remain in the position shown in Fig. 2 or be moved one, two, or three positions and carry with it the ratchet I55, sleeve I25, and type segment llil. Therefore. either row I8I, I82, or I84 of type segment Iii! may occupy a posi- 'tion beneath hammer head I36 of type hammer I81.

At the beginning of each revolution of shaft GIl,-cam I88 presents one of its high parts to a resetting bail I89 which is pivoted at I9! and back in a rotary direction one half or one and one half steps according to the manner in which it was stepped for the fifth element of the previous signal code combination. However, the type segment iQI will remain in the initial rotary po sition occupied during the previous signal code combination.

Thus far. the selector mechanism has been described in connection with the figures case position as shown schematically in Fig. 32. A description will now be given of the manner in which case shifting operations are performed to move the type segment It! from the figures to the letters position and back to the figures position.

It will be assumed that the type segment Ifii has been operating in the figures or shift position and it is now desired to shift to the letters or unshift position. When the unshift or all marking signal is received, slide rack 228 (Fig. 8) will be moved to the left in a position with its notch I54?- directly underlying cross piece N5 of a bail idl, which is pivoted at I93 on bell crank 95 and urged clockwise by spring 295. Bell crank it? in turn is pivoted at 282 and has an arm 263 which pursues the periphery of cam 284 carried by shaft At this time, the low part of slide rack is also directly below cross piece I93 of bail 59?. Further, at this time low part 20? of slide rack 45 i (Fig. 7) is also directly below cross piece 963 of ball :97. Under the afore-describ-ed conditions cross piece lfio of bail IQ! drops into notch 28% of slide rack I23. At the start of enext succeeding half revolution of shaft fol-lower of bell crank Id will ride up the high part of cam 2&5 and by means of bail I97 will draw slide rack I29 to the left, to the position shown in Fig. 14 which is the letters or unshift position. As will be noticed by an inspection of Fig. 14, pin I2I of lever H3 is cammed out of the high part of slot I22 of slide rack I23, into the low part of slot 8 of slide rack 529. When slide rack 529 moves to the position shown in Fig. 14, a latch 209 pivots clockwise as viewed in Fig. 6 about shaft 2H and a forwardly extending flange 252 rops over the 223 of slide I2 5 to hold slide 29 in the letters posit on. This is necessary since there is new tez Ilency of spring 2M, interconnected to levers H5 and lid, to contract and thereby cause pin till to push slide lid to the right and move .g" ien't counterclockwise.

I2! is now in effective of slide rack I29. Now, in response to spacing impulses received in either of the fi st two signal elements of a signal code engagement with slot co =bination, lever II8 will pull slide 129 further to the left and rotate type segment IOI further in a clockwise direction to one of the positions shown in Figs. 15, 16, and 17. Thus, in letters or shift position, there are again four possible initial rotary positions including th position shown inl' 'ig. 14, in which the first impulses would be marking the type t me would not move during receipt of t two impulses.

Again the type segment ration.

On receipt of the shift signal (the third elet f the code spacing), cross piece 2IB of a Ell which is pivoted at 2II will be opposite h of slide I29, notch 255 of pawl I54 bail I As a result, when bail 2H pivots counterclockwise, its projection 220 will engage flange 2H9 of latch 299 and pivot this latch also countercloclaiwise. This raises flange 2I2 out of the path of part 2H3 of slide rack I29, enabling spring 2% to return the type segment IOI to the figures or shift position as pin IEI is cammed once more to the upper part of slot I22 of slide rack I23. It will be noted that latch 209 and hail All are connected by means of a tensioned spring 222 which tends to pivot members 203 and 2!? in opposite directions.

Operation of print hammer IB'l will now be described with particular reference to Fig. 10. Print hammer I83, which carries at its free end hammer head I86, is pivoted at 223 and normally urged clockwise direction by means of 5 'ng Just at the end of a half revolushaft after type segment IilI has been to its selected position, follower proeclon 226 drops to the low part of cam 221 a. d a printing impression is made on tape 228 by hammer head Stop 229A may be of resilient material so that print hammer I3? returns with a quick rebound and leaves a sharp, clear impression on tape 228.

As printing hammer I57 operates, it also causes the operation of the tape feeding means in a manner now to be described. Print hammer i5? is slotted at 229, at which point it is engaged by a pin 23! carried by a tape feeding lever 252 which is pivoted about rod 233. The opposite end of lever 232 has pivoted thereto tron of 

